One

Chris hit him. The sound of the punch was flat and pathetic in this dead space. Jane felt a brief flare of pain in the lower left side of his jaw and thought he heard a distant scream, like those that had haunted them on their last few nights in the countryside.

Angela and Brendan turned away. Becky and Aidan watched with open mouths. Nance seemed excited, turned on almost, but confused too; perhaps she had been expecting a fight. Jane's pacific reaction was not in her copy of the script.

Jane readjusted his goggles, removed the air filter from his mouth and spat. Clean. 'What are you thinking, Chris?' Becky asked. 'We survived this terrible thing. There are hundreds of thousands, probably more like millions of people dead, and you're giving someone a slap because they said something you didn't like? Jesus.'

'Jesus,' Aidan said.

Jane kept his mouth shut. He stared at Chris, seeing the fight crumble out of him. Chris held up a finger; his hand was shaking violently: all that adrenaline crammed into his muscles and nowhere to go.

'A warning,' Chris said, but his voice could not invest in the weight of what he was trying to say.

They weren't safe.

As soon as they moved on they heard whooping noises again. Sounds of joy taken by some as yet unknown quantity into the realms of nightmare. These were violence sounds, death sounds. They carried on the wind currents like vengeful ghosts. Angela pushed herself up from the wheelchair and cried out: 'Leave us alone!'

Jane put a hand on her shoulder but it was too late. The whooping had stopped. Now they could hear determined footsteps slapping towards them.

'Keep your heads down,' Jane said. 'Don't make eye contact. Give them what they want. Don't give them an excuse to hurt us.'

There were six of them – five men and a girl, all of indeterminate age – and they came sprinting out of Castles Farm Road. They did not look good. Their heads had either been shaved to the quick or burned back almost to bone. They looked like something peeled and bruised and sore: too pink, purple and moist. Their blasted faces carried eyes that were overly bright, too intense. Jane wondered if they could focus properly; it was clear they had taken drugs of some sort. And then he saw the melted eyelids, the skin hanging off them like strips of torn material, and he understood why. They were not going to live for long.

'You!' one of them screamed, and they all swerved towards Jane, like starlings at dusk.

Jane again cursed their lack of a weapon, especially when he saw the ice axes hanging from their belts. He hoped that a lack of obvious threat might work in their favour; Angela and Aidan too. The gang didn't stop moving, even when they were within metres of their quarry. They prowled and twitched and spat and perspired. Nobody said anything until Angela again rose.

'Sit yourself back down!' the girl screamed. Metal studs poked out of her shoulders. Her shaven head was pockmarked with razor scars and slashes; it was difficult to guess if any were deliberate.

The girl wore a T-shirt bearing the legend I LOVE GIRLS THAT LOVE GIRLS. Some of the men wore knuckledusters. The pain they felt was there in their eyes; you could see it beyond the gauze of narcotics, you could hear it in every laboured inhalation.

'We have painkillers,' Jane said.

One of the men, a tall bull-shouldered figure with lips so dry they had blackened, laughed and unclipped one of the ice axes. He buried it to the hilt in his own thigh. They knew they were going to die.

'We have water too,' Jane said. They were clearly dehydrated. They were high on whatever they had injected or swallowed, but also on the natural chemicals with which their failing bodies had flooded their bloodstreams.

'Fuck your water!' The girl again, stabbing her head into his airspace like a weapon. 'What are you doing here? This is our sweetshop. You been stealing sweets?'

Jane licked his lips. Carefully he said: 'We took some painkillers. Some inhalers. That's all.'

'That's all?' asked the man who had injured himself. He hobbled around them, each stamp of his foot on the ground pumping fresh blood up around the blade embedded in his thigh. 'The fact is, you set foot in our sweetshop. Without express permission.'

Another of the men ducked towards them, squat, boxheaded, his teeth bared, gums bleeding a scarlet wash across them. 'Shoplifters,' he said, 'will be prosecuted.'

'We didn't know,' Jane said. 'You can have it all back. We'll go somewhere else.'

'No. You won't,' said the girl, her words turning to ash. Her eyes were on Jane's throat. She was unhooking her axe; they all were.

Jane could see what was coming. He drove his fist into box-head's face and shouted 'Run.'